Cabinets are square, rectangular or other geometry shape storage devices for storing daily use items like closing and document files, and are widely found everywhere. Cabinets may be classified into wardrobes, cupboards, drawers, etc. Most cabinets, however, do not have illumination devices. Without illumination, users rely on lights emitted from outside of windows or electric lights in the room to recognize and to take items from cabinets. Also, because of illuminating angles, the inside space of cabinets appears darker, making people inconvenient to retrieve or place items in cabinets. For cupboards with more fragile items such as dishes stored inside, it is easy for users to break fragile items therein. Thus, there is a need to provide better illumination inside cabinets.